One

I have oil accumulating on the valley pan and running down the back of the engine/trans and onto the exhaust. Some down onto the alternator. I have changed the valley pan gasket TWICE thinking i didnt do it right the 1st time having only applied gasket sealer on one side. Now i did it again and still have oil accumulating. The check valves under the valley pan i had taken out and cleaned the 1st time, now i couldnt get them out so i left them be. They seemed to work fine. No valve noise. The leakage is worst when i run higher rpms like on the interstate. Running 80 it will leak enough to leave a light cloud of smoke behind... That's just embarassing. Around town its almost non existent. maybe half a qt leakage per tank of fuel on road trips. I do not seem to have excessive engine blow-by and the CV hoses from the valve covers should take care of that just fine. They are not blocked. cam seals are not bad atall, only 1 shows any leaking at all and its just dirty, not oil washed. It has to be something else because i cannot seal the valley pan any better. valve covers do not seem to be leaking or id be seeing oil on the exhaust manifolds imo.
HELP!

dalspaugh

I have an oil leak around the bottom oil pan gasket, I've tried to fix that twice to no avail. What happens with that is, I only get leaks under pressure so at speed it will slowly drip and fly back on to the exhaust (mostly the cats). This is apparent because that section always appears nicely lubed up. I can smell it after a little while.

I also had a leak behind the oil cooler. There is an o-ring behind the cooler. This one actually stopped upon doing the work. It was kind of a pain to do though because it required an oil change and a coolant flush before you can get in there.

I've also read that if the engine gets really hot, the valley pan warps and then there's no way to get a good seal unless you replace it or (I'm thinking) if you put it on a mill and took it down maybe 10 or 20 thousands.

One

Thanks for the reply. My oil cooler is dry. I checked the valley pan cover for flatness using a metal ruler and found it close enough to true that i did not think further action was required. The first time i did he valley pan gasket i actually sanded it down against 800 grit laid down on my work table. I guess i need to check for a head gasket leaking, but as a mechanic i have never run across a head gasket that leaked out oil but not coolant or combustion pressure. So I'm not inclide to do a head gasket just because. I firmly believe in 'if it anit broke, dont touch it' since things always break on an older car that hasnt been apart a dozen times yet.

hubturn

Double check the fittings on the power steering hose for tightness to eliminate that possibility, since it runs in the valley pan area. Check the Power Steering fluid level. I have had these same frustrations, and thought I solved it too, but again have some valley pan fluid collecting. I have done it twice, leveled the pan and the seat with emery paper on flat glass. Some have said to ditch the gasket and use only a gasket compound. Haven't done that yet but may try it. How many times will the Audi Gods let me take off the intake manifold and not trash that braided copper wire on the sensor?

Prospeeder

hate to say it, but theres service buliltens about the 12v engine having oil leaks in the valley from the head gaskets. My old 100 had this problem I did end up removing the heads and replacing the gaskets.

One

Ok. thanks for the replies. I' not loosing any PS fluid, so its not that. It must be the headgasket(s) then. Whenever i go to town on the timing belt/ water pump/ thermostat i might aswell pull the lower intake and the heads off. I need at least 1 cam seal anyway on the driver rear where the camshaft position sensor sits. The head bolts looked like Torx (?)

hubturn

I did the head gaskets too, to clear this up. It seemed to work for a good while. The stock head bolts are one pattern, T-14 Torx socket, and the replacements are probably a special pattern, so that's two new tools. They are stress bolts and have to be replaced, about $40. Gasket kit is about $250, and that includes/leads you into a boat load of "while I'm in there " projects. All the coolant pipe o-rings, put a new coolant bleeder nut in, cam seals, order new injector o-rings 'cause the old ones will leak, the exhaust manifold nuts, downpipe studs & nuts will be a mess, new vacuum hoses, split and clean the intake manifold. Then of course the heads need to be resurfaced. That's all around $500 total not counting the timing belt, water pump etc. I sort of wish I had had the valves done, but I really wish I'd have personally checked the lifter/cam dimension to eliminate any marginal lifters. 12v.org was essential and having a bentley's manual was a great help.

haraldpost

What about checking the crankcase ventilation? I think it is known to get clogged up, and if it is, pressure can build and result in oil leaks, pushing oil past simrings etc.

ky90025

"One" if you want to pin point the source of the leak, you need to clean the engine top and bottom of all oil. I used a engine degreaser and starting from the top (soak the valley pan area) and clean all the oil off, until the engine surfaces are dry and oil free.

Remove all the plastic engine covers, the top and front are easy. If you remove the serpentine belt you can remove the left and right timing belt cover for the front cam seals (take a photo of the covers since the installation is not obvious after removal). Now clean the front cam seals of all oil. Now you have a good view of the engine surfaces. I found it easier to put the covers back if I removed the serpentine belt tensioner. Put the serpentine belt back on.

Now for the oil leak check. You don't want to drive a lot and check for leaks since if your leak is large it will spill over and go all over the place hiding where it is actually leaking from. Also try to run the car at lower speeds and higher rpms since you don't want the wind to get the oil all over the place.

Before you start the car, look at all the surfaces of the engine (use an inspection mirror when you need to) to see what a clean engine surface looks like. This is important for small leaks since without UV dyes the oil leak can look fairly subtle.

For large leaks I would just start the engine in the garage and run at 3000 rpms for a few minutes. Have the car jack stands so that you can check all the suspected leak areas, which include front cam seals, crank seal, upper and lower oil pan gasket, valve covers, passenger side rear cam plug, driver side cam position sensor area, breather hoses that come off the rear valve covers and valley pan and head gasket area. You will have to use a small inspection mirror, and bright flashlight to check for leaks. Make sure your flashlight is super bright! Remove basics things to check in detail. I removed the plastic tube connecting the MAF to the plenium.

Run slight more time and rpm if you don't see a leak. But do this gradually since if you get a lot of oil to leak, it will be hard to see where it is actually coming from and you will have to start all over again with the cleaning.

Myself, as I stated in my recent posts, although I thought I had a leak in the oil pan area since the oil pan was soaked with oil. It's only after I cleaned the engine very carefully and ran the engine gradually checking for oil leaks to start that I realize that the oil pan gasket was fine and so were the cam seals and crank seal. I actually pulled the harmonic balancer off to check the crank seal. It was not leaking! Initially I was convinced that I had a leak in the front part of the engine or oil pan gasket since I had so much oil in this area. But it looks like its only leaking from the valley pan gasket area. With time the oil goes everywhere. I changed the valley pan gasket using "VAP" method and the gasket sealer he recommends (permatex aviation #3).

The valley pan area is hard to check for oil leaks because of the intake manifold and metal coolant pipe is in the way. But shine light from the front to check the front area. And for the rear valley pan area, if you look very carefully there is a slight indented area on the driver side of the valley pan area in the rear, look for accumulation of oil there since it will collect there before flowing over the rear of the engine and covering everything.

Sorry for the long post but I have been going through hell tracking down my AFC engine oil leak

If your head gasket is leaking then you might try removing the valve covers and tightening the head bolts 1/8 turn (search for the procedure).

Good luck!

haraldpost

What is the "VAP" method for changing the valley pan gasket?